I mean philosophy is not exclusive of arts and humanities.?

Answer 1

Although most religions and spiritual beliefs are clearly
distinct from science on both a philosophical and
methodological level, the two are not generally considered
to be mutually exclusive. A majority of humans hold a mix of
both scientific and religious views. The distinction between
philosophy and religion, on the other hand, is at times less
clear.

Answer 2

philosophy means "love of knowledge" or "love of wisdom" so as long as something can be classified under human knowledge, it can be discussed philosophically.
and philosophers have taken on all subjects from arts & humanities to alchemy to astronomy to religion to botany, much to the dismay of people who want to classify things precisely & distinctly